Chemistry Resources

Going green with enzymes: A challenge of modern chemistry is to minimise chemical and energy usage to benefit the planet and make the production of materials cheaper. Thomas Farrugia and Tim Harrison discuss some of the methods available to chemists. This article links to the following topics in your specification: catalysis, proteins, green chemistry and surfactants. Look out for the practice exam questions in this article.

What’s cooking? The impact of cooking on indoor air quality: What and how you cook in your home can affect the air quality and impact your health. But what is emitted and how can it be analysed? This article links to the following topics in your specification: atmospheric chemistry and mass spectrometry.

Answer back: propanoic practicalities: Maurice Carmody explains how to score top marks and avoid common pitfalls in questions on practice experiments. This article links to the following A-level topics: practical techniques (heating under reflux), oxidation of alcohols, mole calculations and reactions/tests for alcohols and carboxylic acids.

Focus on industry: methanal plastics: A look at the manufcaturing processes and uses of three thermosetting polymers. This article links to the following A-level topics: polymers, condensation reactions and materials.

In pictures: colourful chemistry: Iain Smellie presents the colourful results of exposing flower extracts to a variety of solutions.

Lab page: extracts from a garden: Perform your own experiments to produce colourful solutions like these show in in ‘In pictures’ on the previous pages. Iaian Smellie shares some practcial tips to help you start. This article links to the following A-level topics: acids and bases, pH indicators and experimental chemistry.

Making and doing: chemistry crossword: Revision crossword.

Stable and unstable compounds: The enthaply of formation of a compound indicates whether it is thermodynamically stable or not. Simon Cotton looks at some examples. This article links to the following topics on yor specification: molecular shapes: exidation and reduction, oxidation state (number), intermolecular forces, bond energy, endothermic and exothermic reactions and energy changes (thermodynamics). Look out for the practice exam questions in this article.

Substances: do we need fluoride in our water? Ellie Tulk examines the benefits and costs of adding fluoride to water sources. This article links to the following A-level topics: halides, mineral and ions, equilibria and Le Chatelier’s principle.

How science works: biodegradable polymers: Lacey Aspinall examines the three types of biodegradable polymers. This article links to the following A-level topics: polymers (plastics), esters, peptides, hydrolysis reactions, environmental (green) chemistry and materials science.

Landmark DNA discoveries: April 2023 marks the seventieth anniversary of our understanding of the double helix structure of DNA.

Earth’s airglow: a natural lightshow: If you were to hover near the orbit of the International Space Station, roughly 250 miles from the surface of the Earth, you would see vibrant bands of light being emitted from the upper atmosphere. This is the Earth’s airglow. This article links to the following topics: photochemistry; atomic and molecular emission spectra; rate of reaction; properties of gases – pressure, density, diffusion; bouyamcy and the effects of gravity in fluids; Earth’s atmosphere and climate.

Lab page: chemistry in the kitchen: determining an activation energy: How do you determine the activation energy for the reaction of an acid with a base? An undergraduate research project has established a simple, inexpensive and accurate method that can be carried out at home, without specialist equipment. This article links to the following topics: acid-base reactions; rates of reaction; reaction kinetics; practical chemistry. Look out for the practice exam questions in this article.

Creating flavours in cheese: All cheese starts with the same basic ingredients, but clever chemistry conjures up a wealth of different flavours. This article links to the following topics: amno acids; amines; carbonyl compounds, aldehydes and ketones; carboxylic acids; enzymes; esters; oxidation and reduction. Look out for the practice exam questions in this article.

Focus on industry: chlorine: Chlorine is produced from rock salt (sodium chloride), a readily available starting material. This is achieved by electrolysis of salt solution, with sodium hydroxide being an important by-product. This article links to the following topics: industrial processes; electrolysis; redox (reduction/oxidation) chemistry; Le Chatelier’s principle.

Making and doing: chemistry crossword: Revision crossword.

How science works: optimising catalysed reactions: the role of analytical chemistry: Analytical techniques, such as infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS), are invaluable tools in chemistry. For example, pharmaceutical manufacturers can check the purity of a product before it is given to patients. This article links to the following topics: catalysis; ligands; synthetic reactions; infrared (IR) spectroscopy; mass spectrometry (MS); nuclear magnetic resonance (NMR) spectroscopy.

Green chemistry: modernising organic redox reactions through electochemistry: Chemical reactions that change the oxidation state of organic molecules are crucial to the synthesis of pharmaceuticals, agrochemicals, polymers, fragrances and flavourings. In the pharmaceutical industry, redox reactions are responsible for 15% of reactions used to make medications. This article links to the following topics: oxidation and reduction (redox reactions); primary, secondary and tertiary alcohols; oxidation of alcohols; carbonyl compounds; industrial processes. Look out for the practice exam questions in this article.

Substances: producing polyurethanes: One of the secrets to Adidas’ novel design lies in the use of highly durable and elastic polyurethane, which provides comfort and support to the whole foot while in motion. This article links to the following topics: polymers; organic reactions; curly arrow mechanisms; nucleophilic addition; fractional distillation; green chemistry.

The lotus effect: The leaves of the lotus are self-cleaning. This property is due to the leaves being superhydrophobic – a surface that is extremely difficult to wet. It is also known by a much simpler name – the lotus effect.

Weaponised insects: Insects use intricate chemistry to protect themselves from their enemies. This article links to the following topics on the OCR specification: acid and base reactions; intermolecular forces and volatility; organic functional groups. Look out for the practice exam questions in this article.

Is coffee good or bad for us? Nutrition research is challenging, as it can be difficult to prove or disprove the benefits, or otherwise, of what we eat or drink. Why is it difficult to tell if drinking coffee is good or bad for us, and what are the key chemicals involved? This article links to the following topics in the OCR specification: the Maillard reaction; DNA modification; amino acids; antioxidants and radicals; caffeine. Look out for the practice exam questions in this article.

Wonders of chemistry: cows, isotopes and climate change: The composition of the climate thousands of years ago can be investigated using chemical proxies – such as ruminant animal fatty acids. This article is relevant to the following topics: isotopes; climate change; fatty acids (carboxylic acids).

Value from a greenhouse gas: electrolytic reduction of carbon dioxide: The need to reduce human impact on the environment and slow climate change has resulted in research examining carbon dioxide as a chemical feedstock. This article links to the following topics in the OCR specification: climate change; greenhouse gases; electrolysis; analytical methods; gas chromatography (GC).

Making and doing: chemistry crossword: A revision crossword.

Focus on industry: nitric acid: Nitric acid, used predominantly to manufacture fertiliser, is produced from amonia. This article is relevant to the following topics: equilibria; Le Chatelier’s principle; industrial processes; enthalpy changes.

Encounter: pointing the finger at cocaine users: Fingerprints can now be used to differentiate between individuals who have ingested cocaine and those who have simply touched it. This article is relevant to the following topics: esters; hydrolysis reactions; mass spectrometry.

We are made of star stuff: Astrophysicist Dame Joceyln Bell Burnell explains the origins of the naturally ocurring elements and how all of us are made of stuff from the stars. This article links to the following topics in the OCR specification: chemical elements; the periodic table; atomic structure; isotopes; energy and mass.

Top tips: changing units: The ability to handle units confidently is a vital skills for chemists to have. Peter Wade Wright provides some top tips to help you master them. Look out for the practice exam questions in this article.

The chemistry of skunks: Skunks are infamous for their smelly spray, which they eject when threatened or frightened.

Blast off: the dynamic chemistry of rocket propellants: Dozens of science-focused space missions are planned or underway: observing Earthm exploring other worlds in the solar system and studying farway galaxies. Chemistry plays a crucial role in all of them. This article has links to the following areas of the specification: oxidation and reduction; combustion; rates of reaction; exothermic reactions; energy change (enthalpy); activation energy; stoichiometry; fractional distillation of air to produce liquid oxygen; alkanes and alcohols; Bernoulli principle and conservation of momentum.

Sponge-inspired chemistry: Nature can inspire organic chemists in the synthesis of natural products for biological testing and screening. Here we look at one example from a coral reef. This article links to the following areas of the specification: curly arrow mechanisms; alkaloids; natural products; medicinal chemistry.

Red algae and climate change: Chemists are investigating the organic compounds released by marine algae across the globe, in order to understand their role in climate cooling, thereby potentialy combating climate change. This article links to the following areas of the specification: climate change; radical reactions; atmospheric reactions; nitrogen oxides.

Teaching chemistry to computers: Controlling C-H functionalisation through machine learning. This article links to the following areas of the specification: functional groups; principles of green chemistry; isomers; organic chemistry.

In pictures: fire obsidian: How iridescence creates ‘rainbow rocks’.

Organochlorine compounds: the good, the bad and the toxic: Molecules containing at least one covalently bonded chlorine are wide-ranging and used in diverse applications. Some are useful, while others are of significant environmental concern. This article links to the following areas of the specification: bond energy; functional groups; isomerism; drug discovery; organochlorine compounds and environmental concerns.

Focus on industry: ammonia: The manufacture of ammonia is crucial for the world’s agricultural industry, as all artificial fertilisers that contain nitrogen are produced from ammonia. This article links to the following areas of the specification: industrial processes; enthalpy changes; exothermic and endothermic reactions; Haber process; Le Chatelier’s principle.

Substances: methanol: the future of fuel cells? Could poisonous methanol provide a ‘greener’ fuel? This article links to the following areas of the specification: oxidation of alcohols; fuel cells.

Chemistry crossword: Revision crossword.

Revision note: electrophilic addition reactions: In an addition reaction, one molecule adds to another to form a single, larger molecule. Addition reactions occur with unsaturated compounds, i.e. those containing double or triple bonds. An addition reaction often involves an unsaturaeted organic molecule becoming saturated. This article links to the following areas of the specification: addition reactions; electrophiles; electronegativity; double bonds; curly arrow reaction mechanisms; Markovnikov’s rule; carbocation intermediates.

Belladonna: not just a pretty face: Atropa belladonna is a plant that gained its name from its use in Renaissance Italy. Belladonna means ‘beautiful lady’… However, it is also known by a darker name: deadly nightshade. As this name suggests, the plant contains a lethal poison.